In recent years, insurers have tried to cajole consumers into using less-expensive health-care providers by promising lower co-payments and other cost-sharing breaks for members who select those doctors and hospitals.

Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

Some Anthem Blue Cross and Blue Shield members in New Hampshire, Connecticut and Indiana can receive $50 to $200 if they get a diagnostic test or elective procedure at a less expensive facility than the one their doctor recommended. The offer covers nearly 40 services, from standard radiology tests such as mammograms and MRIs to such surgical procedures as hip and knee replacements, hernia repair, bariatric surgery and tonsillectomies.

"We identified a subset of highly utilized services with cost variances that we thought would have a big impact," says Denise McDonough, regional vice president of sales for Anthem BCBS of New Hampshire. "We want to provide information to members to drive health-care costs down."

It seems to be working. The city of Manchester, N.H., the first employer to pilot Anthem's Compass SmartShopper program in January 2010, has saved more than $250,000 in health-care costs in two years, even after factoring in the cash rewards paid to the 476 members who have participated.

The differences in costs can be eye-popping. According to Anthem data, in Manchester a hernia repair ranges in price from $4,026 on the low end to $7,498 on the high end. A colonoscopy could cost $1,450 to $2,973.

"It was a huge eye-opener for us," says Jane Gile, human resources director for the city government.

It, of course, can also save money for employees who haven’t met their plan’s deductible.

Here's how the SmartShopper program works. At least 24 hours before a member has a scheduled service, he or she calls a toll-free number or logs on to a Web site to get a list of lower-cost local providers.

If a doctor has referred someone to a location that's not on the list of cheaper providers, the member can request that the doctor change the referral. If the physician is performing the procedure, the member can ask that the doctor do it at a cheaper location.

After the provider submits the claim and Anthem pays it, the insurer compares the records of online and telephone inquiries made by the member to the SmartShopper program. If the member chose to get care at a low-cost provider identified by the program, he gets a check in the mail within 60 days. (The amount is usually about $100, but it varies with the size of the amount saved.) An employee who has not yet met his annual deductible would also save directly on the cost of the treatment.

If the member wants to stick with his doctor's initial plan and forgo the cash bonus, no problem. The program is entirely voluntary.

Physician groups have some concerns. "It appears as though the decision is being made by the health plan, and tiering of providers is being made simply on an economic basis," says Scott Colby, executive vice president of the New Hampshire Medical Society. “We have concerns about giving economic incentives without giving weight and credence to quality measures."

It's a fair criticism, insurers concede. Listed providers are licensed and credentialed, but quality indicators such as complication rates aren't factored in. "It's a first-generation set of data," says Eric Schultz, president and chief executive of Harvard Pilgrim Health Care. "We all have a long way to go on performance data."

Likewise, the Compass SmartShopper FAQ page says, “It is up to you to talk to your doctor or research online at anthem.com to determine your quality requirements.”

For simple diagnostic lab and radiology procedures, choosing providers based primarily on cost is probably fine, says Ha Tu, a senior researcher at the Center for Studying Health System Change, a Washington-based think tank. "But when you start talking about surgery, it's hard to argue that quality doesn't vary quite a bit, and people shouldn't be making these decisions purely on cost."

Physicians are also concerned that programs such as SaveOn and SmartShopper may hinder care coordination among providers at a time when such coordination is considered key to managing patients' health and controlling health-care costs.

When the SmartShopper program was introduced, some Manchester city employees were skeptical, says Gile. But many have come around.

Gile herself has used the program three times: twice for screening mammograms and once for a colonoscopy. She had a good experience each time. By choosing a lower-cost provider for the tests, she qualified for cash rewards of a few hundred dollars altogether, she says.